I agree... just trying to explain to myself how the nothing-bred dogs I've been around became hog dogs... cuz it dang sure wasn't genetics...
What you said here proves how the "want to" of a dog is what it really takes. Even those nothing bred dogs that have the want to can make a hogdog, I've seen dogs from the pound make a dog. But without that want to I don't believe any man can train a dog to hunt or be a hogdog. If you figure it out you can ride around picking up stray dogs and in no time be a rich man..
When you do get that dog with the want to and you want to capitalize on it and reproduce it then linebreeding is what will do it. Take him and breed him to a linebred female that's what you like and linebreed from there, That's what will give you consistant hogdogs. But take that dog and breed him to a bunch of non related scatterbred dogs and you will be spinnin your wheels and no amount of training will make your wagon roll, IMO...